Synthesis and isolation of metal alkoxides

ABSTRACT

A method for synthesizing highly soluble metal alkoxides includes the step of reacting a tertiary alcohol having the formula:  
                 
 
     wherein R 1 , R 2  and R 3  are, independently, the same or different, an alkyl group, an alkenyl, an alkynyl group or an aryl group, and at least one of R 1 , R 2 , and R 3  is a group of at least 3 carbon atoms, with at least a stoichiometric amount of a metal reagent. The metal reagent is generally a group I metal, a group II metal, zinc, a metal alloy of a group I metal, a metal alloy of a group II metal, a metal alloy of zinc, a compound of a group I metal, a compound of a group II metal or a compound of zinc.

FIELD OF THE INVENTION

[0001] The present invention relates to metal alkoxides and to thepreparation and isolation of metal alkoxides, and especially, to metalalkoxides that are liquid when pure and/or exhibit increased solubilityin a wide variety of solvents, and to methods of preparation of suchmetal alkoxides.

BACKGROUND OF THE INVENTION

[0002] Metal alkoxides, and particularly alkali metal alkoxides, arewidely used in industry as catalysts and as stoichiometric reagents.These reagents are used in diverse reaction chemistries such asalkylation, isomerization, rearrangements, condensations,transesterifications and eliminations. See, for example, D. E. Pearson,C. A. Buehler Chemistry Reviews 74, 45 (1974).

[0003] As pure solid compounds, these materials are ionic in characteras a result of the strongly electropositive nature of the metals. See,for example, D. C. Bradley, R. C. Mehrotra, D. P. Gaur, Metal Alkoxides,Academic Press, London (1978). For derivatives of the same element, thecovalent character of the metal-oxygen bond increases with the greaterinductive effect of the alkyl group. For example, a tertiary butoxidehas a higher covalent character than the corresponding primaryn-butoxide. The trend in covalent character relative to the counter ionin the case of alkali metals, for example, is that lithium alkoxides aremore covalent than sodium or potassium alkoxides. This phenomenon,coupled with steric factors, leads to a slightly greater inherentstability of the isolated solid tertiary alkoxides. Unfortunately, thesecaustic solids readily react with atmospheric water and carbon dioxide.Furthermore, these solid metal alkoxides are rather dusty, which can beproblematic when handled on a large scale. Some of the primary alkoxidesare also prone to spontaneous combustion in air. See Y. El-Kattan, J.McAtee, “Sodium Methoxide,” Encyclopedia of Reagents for OrganicSynthesis, 4593, Ed. L. A. Paquette, John Wiley and Sons, NY (1995).

[0004] To provide a safer material, metal alkoxides are often dissolvedin a solvent. In general, liquids are, for example, easier to transferfrom drums or cylinders into reactors (reducing the exposure of humanhandlers to dangerous materials), more easily kept under an inertatmosphere, and provide more options for modes of addition to thesubstrate. Unfortunately, alkali metal alkoxides and other metalalkoxides exhibit only rather low solubility in the alcohols from whichthe alkoxides are made, usually in the range of 2-25 wt %. For example,sodium isopropoxide is only soluble up to about 2 wt % in isopropanol.The low solubilities of many alkoxides have been attributed to the ioniccharacter and the extent of oligomerization or polymerization insolution. Another factor affecting solubility in an alcohol solvent isthe propensity of alkoxides to form insoluble alcoholate complexes withthe alcohol. Metal alkoxides are somewhat more soluble in polar etherealsolvents such as tetrahydrofuran and the polyethers (glymes). However,even in ethers, the solubility is generally less than 50%, especially ator below room temperature (that is, at or below 25° C.). Moreover, therange of polar solvents is somewhat limited as a result of thereactivity of the alkoxide. Furthermore, in some cases the solvent ofchoice for the desired reaction involving a metal alkoxide is notcompatible with the alkoxide or the metal alkoxide is insoluble therein.

[0005] It is very desirable to develop metal alkoxide reagents thatfacilitate the diverse reactions in which those reagents are use.

SUMMARY OF THE INVENTION

[0006] The present invention provides generally a method to producerelatively highly concentrated solutions of metal alkoxides in a widevariety of solvents. Solvents suitable for use in the present inventioninclude aliphatic and aromatic hydrocarbons, and polar aprotic solventssuch as dimethyiformamide (DMF) and ethers. Preferably, the solubilityof the metal alkoxide in the solvent is at least approximately 25 wt %.More preferably, the solubility of the metal alkoxide in the solvent isat least approximately 50 wt %. Most preferably, the solubility of themetal alkoxide in the solvent is at least approximately 75 wt %. Thesesolubilities are achievable at relatively low temperature. Preferably,for example, these solubilities are exhibited in a temperature range ofapproximately −40° C. to approximately 50° C. More preferably, thesesolubilities are exhibited in a temperature range of approximately −25°C. to approximately 25° C. Most preferably, these solubilities areexhibited in a temperature range of approximately 0° C. to approximately25° C. Surprisingly, the relatively high solubilities of the presentinvention are achievable even in aliphatic hydrocarbons and aromatichydrocarbons.

[0007] The present invention also provides for isolation andcharacterization of the first pure liquid alkali metal alkoxide reagentand other liquid metal alkoxide reagents. As used herein, the terms“pure” or “neat” refer to a liquid having a purity of at leastapproximately 97 wt % (that is, the liquid is at least 97% metalalkoxide by weight). The purity is more preferably at leastapproximately 98 wt %. Most preferably, the purity is at leastapproximately 99 wt %. Unlike current metal alkoxide reagentcompositions, the neat, liquid alkoxide reagents of the presentinvention are highly miscibile in all proportions with a wide variety ofsolvents, including, for example, aliphatic hydrocarbon solvents such ashexane and heptane or aromatic hydrocarbon solvents. Other suitablesolvents include ethers and polar aprotic solvents. Furthermore, thecompositions of the present invention are relatively easy to handle ortransport. Moreover, the highly concentrated and/or neat liquid metalalkoxide reagents of the present invention allow higher reactor loadingthan is possible with current compositions, thereby maximizingproductivity.

[0008] In one aspect, the present invention provides a method forsynthesizing highly soluble metal alkoxides comprising the step of:reacting a tertiary alcohol with at least a stoichiometric amount of ametal reagent. Preferably, the reaction proceeds for a period of timesufficient for the reaction to go to completion. The metal reagent ispreferably a group I metal, a group II metal, zinc, a metal alloy of agroup I metal, a metal alloy of a group II metal, a metal alloy of zinc(suitable metal alloys, include, for example, NaK, NaHg or KHg), acompound of a group I metal, a compound of a group II metal or acompound of zinc (suitable, metal compounds include, for example, LiH,NaH, KH, Et₂Zn or Bu₂Mg). Preferred metals for use in the presentinvention include K, Li, Na, Cs, Mg, Ca or Zn. Likewise, metal alloysand metal compounds for use in the present invention preferably includeK, Li, Na, Cs, Mg, Ca or Zn. In the case that a metal is used, thereaction preferably takes place above the melting point of the metal.Preferably, formation of a metal-alcoholate complex is avoided. To avoidforming a metal-alcoholate complex, an excess of metal reagent (forexample, metal, metal alloy and/or metal compound) is preferably used.

[0009] Tertiary alcohols suitable for use in the present inventionpreferably have the general formula:

[0010] (or HOCR¹R²R³) wherein R¹, R², and R³ are, independently, thesame of different, an alkyl group, an alkenyl group, an alkynyl group oran aryl group, and at least one of R¹, R², and R³ is a group of at least3 carbon atoms. Preferably, at least on of R¹, R², and R³ is a branchedgroup of at least 3 carbon atoms. More preferably, at least one of R¹,R², and R³ is a branched group of at least 6 carbon atoms. As usedherein, the term “alkyl group” includes generally branched andunbranched alkyl group of the formula —C_(n)H_(2n+1) (wherein n is aninteger) and cyclic alkyl groups of the formula —C_(m)H_(2m) wherein mis an integer equal to or greater than 3. Alkyl groups preferably have 1to 20 carbons. The term “alkenyl” refers generally to a straight orbranched chain hydrocarbon group with at least one double bond,preferably with 2-20 carbon atoms, and more preferably with 3-10 carbonatoms (for example, —CH≡CHR, —CH₂CH≡CHR, or —CH₂CH≡CHCH₂CH≡CHR, whereinR is, for example, H, an alkyl group, an alkenyl group, an alkynyl groupor an aryl group). The term “alkynyl” refers to a straight or branchedchain hydrocarbon group with at least one triple bond, preferably with2-20 carbon atoms, and more preferably with 3-10 carbon atoms (forexample, —C≡CR, —CH₂C≡CR, or —CH₂C≡CCH₂C≡CR). The term “aryl group”preferably includes generally phenyl and napthyl groups. The term“branched” as use herein refers generally to a group that has at leastone carbon atom attached to at least three other carbon atoms. Examplesof branched groups include, but are not limited to, cyclic alkyl groups,aryl groups, arylalkyl groups and branched acyclic alkyl groups (forexample, an isopropyl group). The alkyl, alkenyl, alkynyl and/or arylgroups of the present invention can be substituted or unsubstituted.Alkyl groups can, for example, be substituted with (that is, one or moreof the hydrogen atoms thereof replaced with) an aryl group (making anarylalkyl group), an alkenyl group and/or an alkynyl group. Alkenylgroups can, for example, be substituted with an alkyl group and/or anaryl group. Alkynyl groups can, for example, be substituted with analkyl group and/or an aryl group. Aryl groups can, for example besubstituted with an alkyl group, an alkenyl group and/or an alkynylgroup.

[0011] In another aspect, the present invention provides a solution of ametal alkoxide of the formula:

[0012] (or R⁴ _(n)MOCR¹R²R³), wherein R⁴ is an alkyl group, an arylgroup or an alkoxyl group, M is a group I metal, a group II metal orzinc, and n is 0 or 1. M is preferably K, Li, Na, Cs, Mg, Zn or Ca. Theconcentration of metal alkoxide in the solvent is preferably greaterthan 50 wt %. More preferably, the concentration of the metal alkoxideis at least 75%. If M is a monovalent metal ion, n is 0. If M is adivalent metal ion, n is 1. Suitable solvents include aliphatichydrocarbons, aromatic hydrocarbons, and polar aprotic solvents. As usedherein, the term “alkoxyl group” refers generally to groups having theformula —OR⁵, wherein R⁵ is an alkyl group (substituted orunsubstituted). R⁵ can, for example, be —CR¹R²R³.

[0013] In still another aspect, the present invention provides acompound having the formula:

[0014] (or R⁴ _(n)MOCR¹R²R³), wherein M, R¹, R², R³, R⁴ and n are asdefined above. Unlike prior metal alkoxide reagents, the metal alkoxidesof the present invention are liquid at or below 25° C. and having apurity greater than approximately 97 wt %. Examples of such metalalkoxide compounds include, but are not limited to, potassium, sodiumand lithium (3,7-dimethyl-3-octanoxide),

BRIEF DESCRIPTION OF THE FIGURES

[0015]FIG. 1 illustrates chemical reactions of alkali metals and alkalimetal compounds with 3,7-dimethyl-3-octanol or with linalool to producethe corresponding alkali metal alkoxides.

[0016]FIG. 2 illustrates a chemical reaction of diethylzinc with3,7-dimethyl-3-octanol to produce the corresponding ethyl zinc3,7-dimethyl-3-octanoxide.

[0017]FIG. 3 illustrates the chemical reaction of two other tertiaryalcohols with a metal to form the corresponding liquid metal alkoxide.

DETAILED DESCRIPTION OF THE INVENTION

[0018] In general, the present invention provides metal alkoxides ofincreased solubility in a broad range of solvents. Moreover, for thefirst time, a number of the metal alkoxides of the present inventionwere isolated as a neat liquid (that is, substantially pure orsubstantially solvent free as defined above). In general, the metalalkoxides of the present invention are preferably synthesized fromtertiary alcohols with at least one branched substituent.

[0019] For example, a new alkoxide has been prepared by reactingpotassium metal with 3,7-dimethyl-3-octanol in a hydrocarbon solvent.The resulting alkoxide, potassium 3,7-dimethyl-3-octanoxide (KDMO), canbe produced as high weight percent solutions and is a liquid when neat.In addition, the sodium and lithium alkoxides of 3,7-dimethyl-3-octanolwere found to be liquids when pure. Other liquid metal alkoxides can bemade from this alcohol with a counterion of, for example, calcium,magnesium, or zinc.

[0020] Other tertiary alcohols can be easily converted into alkoxides bythe same methods as described for the alkali metal3,7-dimethyl-3-octanoxide. Tertiary alcohols suitable for use in thepresent invention preferably have the general formula:

[0021] (or HOCR¹R²R³) wherein R¹, R², and R³ are, independently, thesame of different, an alkyl group, an alkenyl group, an alkynyl or anaryl group, and at least one of R¹, R², and R³ is a group of at least 3carbon atoms as described above. Examples of alcohols suitable for usein the present invention include, but are not limited to,3,7-dimethyl-3-octanol, linalool, dimethylbenzenepropanol,2-methyl-2-hexanol and 3-ethyl-2,2-dimethyl-3-pentanol.

[0022] The metal alkoxides of the present invention are preferablyprepared by the reaction of a metal and the corresponding alcohol. Othersynthetic methods involving the reaction of metal alloys (for example,NaK) or metal compounds (for example, metal hydrides, metal hydroxidesor alkylmetal compounds) are also suitable. However, synthetic methodsusing metal alloys or metal compounds (rather than the correspondingmetal) can be either quite expensive or result in metal alkoxideproducts of lower purity. Reaction of the metal and the correspondingalcohol is thus preferred when possible in the present invention.

[0023] In the case of alkali metal alkoxides, potassium tertiaryalkoxides are stronger bases than primary and secondary alkoxides ofpotassium, sodium or lithium when compared in the same solvent. Anotherproperty of tertiary alkoxides is their relatively weak nucleophilicity.As a result, interfering reaction pathways to impurities are diminished.A tertiary potassium alkoxide produced from an alcohol such as3,7-dimethyl-3-octanol displays such desirable properties. In the caseof 3,7-dimethyl-3-octanol, R¹ is a methyl group, R² is an ethyl groupand R³ is a 4-methyl pentyl group.

[0024] In one set of studies, potassium 3,7-dimethyl-3-octanoxide(KDMO), was prepared by the reaction of potassium metal with3,7-dimethyl-3-octanol in heptane in a pressure reaction vessel. Thealcohol was metered into a molten potassium dispersion in the solvent.Reaction temperatures were preferably maintained above 100° C. Forexample, in several experiments the reaction temperature was maintainedat approximately 110° C., followed by a heat soak at 125-130° C. for atleast approximately 2 hours. The reaction pressures were generally above1 atm. In several studies, the potassium alkoxide solution was preparedas a 50 wt % solution in heptane. Further studies demonstrated that70-75 wt % solutions were easily prepared by the same method.Hydrocarbon solvents other than heptane, as well as ether solvents (forexample, tetrahydrofuran) or polar aprotic solvents can also be used inthe synthetic methods of the present invention. Furthermore, the neatpotassium 3,7-dimethyl-3-octanoxide can be prepared without solvent byaddition of potassium to neat 3,7-dimethyl-3-octanol (one equivalent).

[0025] Potassium 3,7-dimethyl-3-octanoxide was subsequently isolated byvacuum distillation of the heptane from the product. The pure potassiumalkoxide exists as a liquid. Attempts to induce crystallization of thepotassium 3,7-dimethyl-3-octanoxide were unsuccessful. Freezing pointdetermination showed that this alkoxide does not crystallize, butinstead becomes a glassy solid around −54° C.

[0026] Sodium 3,7-dimethyl-3-octanoxide was prepared in a methodanalogous to that described above for potassium3,7-dimethyl-3-octanoxide by the addition of the alcohol to moltensodium in heptane in a high pressure reaction vessel. The sodiumalkoxide was also isolated as a neat liquid product.

[0027] Lithium 3,7-dimethyl-3-octanoxide was prepared by the reaction oflithium hydride with 3,7-dimethyl-3-octanol in heptane, because of therelatively high melting point of lithium metal. Like the potassium andsodium compounds, the lithium alkoxide product was isolated as a neatliquid.

[0028] Other metal alkoxides isolated as a neat liquid include metaldimethylbenzenepropanoxides, metal 2-methyl-2-hexanoxides and metal3,7-dimethyl-1,6-octene-3-oxides.

[0029] In the reactions of the present invention, addition of excessalcohol or incomplete reaction of the metal and alcohol can result inthe formation of an insoluble solid alcoholate complex. Use of a slightexcess of metal as well as longer reaction times can eliminate formationof the alcoholate complex.

EXPERIMENTAL EXAMPLES Example 1

[0030] Potassium 3,7-dimethyl-3-octanoxide, KDMO

[0031] Potassium metal (237 , 6.061 moles) was combined with heptane(1100 mL) in a high pressure reaction vessel and heated to approximately110° C. with the back-pressure regulator set at 30 psig. The dry alcohol(886 g, 5.590 moles) was then slowly added into the reactor. During thereaction hydrogen gas was evolved. The alcohol was added over a 2 hourson the 1-gallon scale. Upon complete addition of the alcohol, thetemperature was increased to approximately 125° C. for a period of 2 hrsto ensure the reaction went to completion. Evolved gas was noted aftercomplete alcohol addition, but ceased shortly thereafter. The solutionwas then filtered resulting in a clear, water white potassium alkoxidesolution.

[0032] Isolation of pure alkoxide potassium 3,7-dimethyl-3-octanoxidewas accomplished by vacuum distillation of the heptane from the product.The liquid obtained was titrated for base content and found to be 99.3%pure. Spectral data are as follows: ¹H NMR (250 MHz, C₆D₆)1.82 (m), 1.43(q,br), 1.37-1.24 (m), 1.14 (d),1.00 (t) ppm; ¹³C NMR (62.9 MHz, C₆D₆)71.7, 49.1, 42.9, 40.3, 34.5, 30.2, 25.5, 24.7, 11.5 ppm.

Example 2

[0033] Sodium 3,7-dimethyl-3-octanoxide

[0034] Sodium hydride was combined with heptane in a round bottom flaskand heated to approximately 100° C. The dry alcohol was then slowlyadded into the reaction mixture. During the addition hydrogen gas wasevolved. Upon complete addition of the alcohol, the mixture was heatedfor a period of 1 hr to ensure the reaction proceeded to completion.This was confirmed by the lack of an alcohol hydroxyl peak in theinfrared spectrum. The solution was then filtered, resulting in a paleyellow solution.

[0035] Isolation of pure alkoxide sodium 3,7-dimethyl-3-octanoxide wasaccomplished by vacuum distillation of the heptane from the product. Theliquid obtained was titrated for base content and found to be 99.8%pure. Spectral data are as follows: ¹H NMR (250 MHz, C₆D₆) 1.71-1.63(m), 1.51-1.27 (m,br), 1.16 (s), 1.07-0.99 (multiple peaks) ppm; ¹³C NMR(62.9 MHz, C₆D6) 69.6, 48.1, 40.9, 39.2, 28.5, 24.1, 23.0, 10.0 ppm.

Example 3

[0036] Lithium 3,7-dimethyl-3-octanoxide

[0037] Lithium hydride and heptane were combined in a round bottom flaskand heated to reflux. The dry alcohol was then slowly added into themixture. Upon complete addition of the alcohol, the mixture was heatedfor a period of 1 hr to ensure the reaction proceeded to completion. Thesolution was then filtered resulting in a clear, pale yellow, lithiumalkoxide solution.

[0038] Isolation of the pure alkoxide, lithium 3,7-dimethyl-3-octanoxidewas accomplished by vacuum distillation of the heptane from the product.The liquid obtained was titrated for base content and found to be 98.7%pure. Spectral data are as follows: ¹H NMR (250 MHz, C₆D₆) 1.71-1.54(m), 1.46-1.31 (m), 1.08-0.98 (m); ¹³C NMR (62.9 MHz, C₆D₆) 71.4, 46.3,40.5, 37.9, 30.8, 28.5, 24.3, 23.0, 10.5 ppm.

Example 4

[0039] Potassium 2-methyl-2-hexanoxide

[0040] Potassium hydride was combined with THF in a round bottom flask.The alcohol, 2-methyl-2-hexanol, was then slowly added to the flask.During the addition hydrogen gas was evolved. The reaction mixture wasstirred for 1 hour at ambient temperature to ensure the reactionproceeded to completion. The infrared spectrum confirmed the completereaction of the alcohol. The solution was then filtered resulting in aclear, pale yellow solution.

[0041] Isolation of the pure alkoxide was accomplished by vacuumdistillation of the THF from the product. Spectral data are as follows:1H NMR (250 MHz, C₆D₆) 1. 51 (p), 1.34-1.25 (m), 1.15 (t), 1.05 (s, br)ppm; ¹³C NMR (62.9 MHz, C₆D₆) 68.1, 50.1, 35.3, 28.8, 24.7, 14.9 ppm.

Example 5

[0042] Sodium 2-methyl-2-hexanoxide

[0043] Sodium hydride was combined with heptane in a round bottom flask.The alcohol, 2-methyl-2-hexanol, was then added to the slurry. Noreaction occurred upon the addition of the alcohol to the hydride. Themixture was heated to reflux under nitrogen for a period of 2 hours tocomplete the reaction. The infrared spectrum confirmed completereactivity of the alcohol. The solution was filtered, resulting in aclear, orange solution.

[0044] Isolation of the pure alkoxide was accomplished by vacuumdistillation of the heptane from the product. Spectral data are asfollows: ¹H NMR (250 MHz, C₆D₆) 1.52 (m, br), 1.44 (m,br), 1.33 (s),1.02 (t) ppm; ¹³C NMR (62.9 MHz, C₆D₆) 68.6, 50.7, 33.8, 29.7, 24.3,14.5 ppm.

Example 6

[0045] Sodium Dimethylbenzenepropoxide

[0046] Sodium hydride (9.0 g, 0.375 moles) was combined with heptane(250 mL) in a high pressure reaction vessel and heated to 60° C. withthe back-pressure regulator set to 26 psig. The alcohol,dimethylbenzenepropanol (32 g, 0.195 moles), was then slowly added (overa period of approximately 30 minutes) into the reactor. Upon completeaddition of the alcohol, the temperature was increased to 100° C. for aperiod of 3 hours to ensure the reaction went to completion. Thesolution was then filtered resulting in a pale yellow solution.

[0047] Isolation of the pure alkoxide was accomplished by vacuumdistillation of the heptane from the product. The liquid obtained wastitrated for base content and found to be greater than 99% pure.Spectral data are as follows: ¹H NMR (250 MHz, C₆D₆) 7.21-7.06 (m),2.60-2.53 (m), 1.70 (m,br), 1.17 (s); ¹³C NMR (62.9 MHz, C₆D₆) 143.5,128.7, peak under solvent, 125.9, 68.2, 53.6, 34.1 ppm.

Example 7

[0048] Lithium Dimethylbenzenepropoxide

[0049] Lithium hydride was combined with heptane in a high pressurereaction vessel and heated to 60° C. with the back-pressure regulatorset to 26 psig. The alcohol, dimethylbenzenepropanol, was then slowlyadded into the reactor. Upon complete addition of the alcohol, thetemperature was increased to 100° C. for a period of 2 hours to ensurethe reaction went to completion. The solution was then filteredresulting in a pale yellow solution.

[0050] Isolation of the pure alkoxide was accomplished by vacuumdistillation of the heptane from the product. The liquid obtained wastitrated for base content and found to he 99.3% pure. Spectral data areas follows: ¹H NMR (250 MHz, CDCl₃) 7.24-7.05 (m), 2.61-2.54 (m),1.69-1.62 (m), 1.17 (s) ppm; ¹³C NMR (62.9 MHz, CDCl₃) 143.3, 128.6,128.4, 125.8, 69.2, 50.9, 33.1 ppm.

Example 8

[0051] Potassium 3,7-dimethyl-1,6-octene-3-oxide

[0052] Potassium metal was combined with heptane in a high pressurereaction vessel and heated to approximately 100° C. with theback-pressure regulator set at 25 psig. The dry alcohol (linalool) wasthen slowly added into the reactor. The alcohol was slowly added to themetal. Upon complete addition of the alcohol, the temperature wasincreased to approximately 120° C. for a period of 4 hrs to ensure thereaction went to completion. The solution was then filtered resulting ina clear, pale yellow potassium alkoxide solution.

[0053] Isolation of pure alkoxide was accomplished by vacuumdistillation of the heptane from the product. The liquid obtained wastitrated for base content and found to be 99.3% pure. Spectral data areas follows: ¹H NMR (250 MHz, C₆D₆) 6.19 (m), 5.50 (m), 4.94 (m), 2.06(m), 1.82 (t), 1.41 (m), 1.10 (s) ppm; ¹³C NMR (62.9 MHz, C6D₆) 156.9,129.8, peak under solvent, 106.3, 72.4, 49.2, 32.6, 26.1, 25.3, 17.9ppm.

Example 9

[0054] Sodium 3,7-dimethyl-1,6-octene-3-oxide

[0055] Sodium metal was combined with heptane in a high pressurereaction vessel and heated to approximately 105° C. with theback-pressure regulator set at 25 psig. The dry alcohol was then slowlyadded into the reactor. Upon complete addition of the alcohol, thetemperature was increased to approximately 120° C. for a period of 4 hrsto ensure the reaction went to completion. The solution was thenfiltered resulting in a clear, pale yellow sodium alkoxide solution.

[0056] Isolation of pure alkoxide was accomplished by vacuumdistillation of the heptane from the product. The liquid obtained wastitrated for base content and found to be % pure. Spectral data are asfollows: ¹H NMR (250 MHz, C₆D₆) 6.17 (m,br), 5.46 (m,br), 5.15 (d), 4.98(d), 2.14 (s,br) 1.78 (s), 1.70 (s), 1.39 (s,br) ppm; ¹³C NMR (62.9 MHz,C₆D₆) 153.2, 130.5, 125.9, 108.7, 71.1, 50.0, 29.1, 26.2, 25.9, 17.7ppm.

Example 10

[0057] Lithium 3,7-dimethyl-1,6-octene-3-oxide

[0058] Lithium hydride was combined with heptane in a high pressurereaction vessel with the back-pressure regulator set at 25 psig. The dryalcohol was then slowly added into the reactor while the reactor washeated. Upon complete addition of the alcohol, the reaction was heatedat approximately 100° C. for a period of 4.5 hrs to ensure the reactionwent to completion. The solution was then filtered resulting in a clear,pale yellow lithium alkoxide solution.

[0059] Isolation of pure alkoxide lithium3,7-dimethyl-1,6-octene-3-oxide was accomplished by vacuum distillationof the heptane from the product. The liquid obtained was titrated forbase content and found to be % pure. Spectral data are as follows: ¹HNMR (250 MHz, C₆D₆) 6.11 (m,br), 5.27 (d), 5.04 (d), 2.10 (m), 1.71 (s),1.63 (s), 1.35 (s,br) ppm; ¹³C NMR (62.9 MHz, CDCl₃) 150.4, 130.9,125.3, 110.5, 71.5, 47.8, 28.7, 25.9, 24.9, and 17.9 ppm.

[0060] Although the present invention has been described in detail inconnection with the above examples, it is to be understood that suchdetail is solely for that purpose and that variations can be made bythose skilled in the art without departing from the spirit of theinvention except as it may be limited by the following claims.

What is claimed is:
 1. A method for synthesizing highly soluble metalalkoxides comprising the step of: reacting a tertiary alcohol having theformula:

wherein R¹, R², and R³ are, independently, the same or different, analkyl group, an alkenyl group, an alkynyl group or an aryl group, and atleast one of R¹, R², and R³ is a group of at least 3 carbon atoms, withat least a stoichiometric amount of a metal reagent selected from thegroup of a group I metal, a group II metal, zinc, an alloy of a group Imetal, an alloy of a group II metal, an alloy of zinc, a compound of agroup I metal, a compound of a group II metal or a compound of zinc. 2.The method of claim 1 wherein the metal reagent is K, Li, Na, Cs, Mg, Caor Zn, an alloy of K, Li, Na, Cs, Mg, Ca or Zn, or a compound of K, Li,Na, Cs, Mg, Ca or Zn.
 3. The method of claim 1 wherein the alcohol is3,7-dimethyl-3-octanol.
 4. The method of claim 3 wherein the metalreagent is K, Li, Na, Cs, Mg, Ca or Zn, an alloy of K, Li, Na, Cs, Mg,Ca or Zn, or a compound of K, Li, Na, Cs, Mg, Ca or Zn.
 5. The method ofclaim 3 wherein the metal reagent is K, an alloy of K, or a compound ofK.
 6. The method of claim 1 wherein the metal reagent is K, Li, or Na,an alloy of K, Li or Na, or a compound of K, Li or Na.
 7. The method ofclaim 1 wherein the concentration of the metal alkoxide in a solvent isgreater than approximately 50%.
 8. The method of claim 1 wherein theconcentration of the metal alkoxide in a solvent is greater thanapproximately 75%.
 9. The method of claim 1 wherein the metal reagent isreacted with neat tertiary alcohol and the reaction provides a generallypure, liquid metal alkoxide.
 10. The method of claim 1 wherein a solventis distilled from the metal alkoxide to provide a generally pure, liquidmetal alkoxide.
 11. The method of claim 9 wherein the alcohol is3,7-dimethyl-3-octanol.
 12. The method of claim 10 wherein the alcoholis 3,7-dimethyl-3-octanol.
 13. The method of claim 7 wherein the solventis an aliphatic hydrocarbon, an aromatic hydrocarbon, or a polar aproticsolvent.
 14. The method of claim 1 wherein the alcohol is linalool,dimethylbenzenepropanol or 2-methyl-2-hexanol.
 15. The method of claim 1wherein an excess of metal reagent is used.
 16. A solution a metalalkoxide of the formula:

wherein R¹, R², and R³ are, independently, the same of different, analkyl group, an alkenyl group, an alkynyl group or an aryl group, and atleast one of R¹, R², and R³ is a group of at least 3 carbon atoms, themetal is a group I metal, a group II metal or Zn, R⁴ is an alkyl groupor an alkoxyl group, n is 0 if the metal is monovalent, n is 1 if themetal is divalent, and the concentration of metal alkoxide in thesolvent is greater than 50 wt %.
 17. The solution of claim 16 whereinthe metal is K, Li, Na, Cs, Mg, Ca or Zn.
 18. The solution of claim 16wherein the concentration of the metal alkoxide is greater than 75%. 19.The solution of claim 16 wherein the metal alkoxide is ametal-3,7-dimethyl-3-octanoxide.
 20. The solution of claim 16 whereinthe solvent is an aliphatic hydrocarbon, an aromatic hydrocarbon or apolar aprotic solvent.
 21. A compound having the formula R⁴_(n)M-(3,7-dimethyl-3-octanoxide), wherein M is a group I metal, a groupII metal or Zn, R⁴ is an alkyl group or an alkoxyl group, n is 0 if themetal is monovalent, n is 1 if the metal is divalent, and wherein thecompound is liquid at or below 25° C. and has a purity greater than 97wt %.
 22. The compound of claim 20 wherein the metal is K, Li, Na, Cs,Mg, Ca or Zn.
 23. The compound of claim 20 wherein the metal is K, Na orLi.
 24. The compound of claim 20 wherein the metal is K.